Electronic services, such as electronic banking, internet commerce, and electronic government services, are becoming more common. Such services require a high level of security, but must also be user-friendly, and not require extraordinary effort on the part of the user to invoke the security protocols. Digital certificates and public key infrastructure (PKI) technologies provide strong data encryption, and are preferred over such technologies as Secure Socket Layer (SSL) for secure transmission between two endpoints. Digital certificates are conventionally issued to a person once that person's identity has been verified, such as by having the user enter a driver's license number, a credit card number, or other identifier associated to the user. An issued digital certificate is uniquely associated to the user, and includes identifying information concerning the user that is used to verify the authenticity of the certificate. Once issued, the user can use the certificate to participate in secure communications, encryption, digital signatures and the like. However, the user not only has to apply for a certificate before accessing the secure services, but must also store and manage the certificates, which has prevented their widespread adoption.
There are also services and products, such as online voting, polling and census-taking, that would benefit from the security offered by digital certificates and PKI, but require that the user remain anonymous. Conventional PKI certificates cannot be used for transmitting or collecting data in such offerings, as identifying information must be collected from the user in order to provide a certificate. Anonymous, single-use certificates have been proposed. For example, providing each potential user with a digital certificate embedded into a dedicated smart card or magnetically encoded on a driver's license has been suggested. Such solutions are generally thought to be impractical due to the large number of certificates required, potentially numbering in the millions for electronic voting or census taking. Issuing certificates on demand for a particular event, such as an election, would also put an unrealistic strain on any system, and would require an unmanageable number of live certificates to be issued at the same time for relatively short periods of use.
Digital certificates that contain just enough information to verify the user, without releasing other personal information, have also been proposed. However, such certificates are still user-specific and based on a user's identity, and must be obtained by the user, via a trusted user identity verification process, prior to gaining access to an electronic service.
It is, therefore, desirable to provide a system and method for issuing digital certificates that are transparent to the user and easily managed by a certificate authority. It is also desirable that the certificates are anonymous or user-independent.